Pupils in comprehensives are disqualifying themselves from top jobs and places at some of the country's best universities because so few are studying a foreign language, a report claims.

Most state schools in England have abandoned a government target to keep at least half their pupils studying a language until the age of 16, the study reveals.

Language learning is now in danger of becoming a "twilight" subject taken only by pupils prepared to stay on after school. It is least popular in schools with a higher than average number of pupils on free school meals, and most popular in private and grammar schools, says the report.

Pupils are shunning languages because they are perceived to be a more difficult option than subjects such as art and drama, while schools feel under pressure to concentrate on "core" subjects such as English and maths so they do not slip down league tables.

In 60% of state schools, fewer than half the pupils are taking a language at the age of 14 this year, compared to 55% the year before. Languages least popular in comprehensives: in 60% of them, three-quarters of pupils are not taking a language at 14.

Studying French, German, Spanish or other languages is now optional at 14 in three-quarters of state schools, compared to 18% of private schools, according to the survey of 668 secondary schools by CiLT, the national centre for languages.

The take-up of languages has been in sharp decline in state schools since 2004, when the government made the subject optional for pupils aged 14 and over.

To stem the decline, the then-schools minister, Jacqui Smith, wrote to secondary headteachers in 2006 ordering them to have at least 50% of pupils studying a language up to 16. But state schools told CiLT this is "unrealistic".

Parents and form teachers often tell children that English is the dominant language in the world and they need not bother to learn foreign languages, the report says.

The school day is so packed that some teachers said they were forced to offer languages as a "twilight" subject, only for pupils who stay on late.

The demise of languages puts pupils from comprehensives – particularly those in deprived parts of the country – at a big disadvantage when they are applying for high-flying jobs, because multinational businesses often demand at least one foreign languages.

Top universities, such as University College London, have started to demand applicants have a foreign language at GCSE and the London School of Economics is considering doing the same.

Kathryn Board, chief executive of CiLT, said: "The need for our young people to learn languages has never been greater, with language skills becoming increasingly important when competing for jobs in the global marketplace.

"In the longer term, we are disadvantaging our young people in the world of employment. There is growing elitism around languages. The intellectual enrichment that comes from learning them is alive and kicking in the independent schools, but dropping very quickly in the state schools."

She called for A-level languages to count for more points on university applications than some other subjects.

Last summer, just 44% of GCSE students took a language, compared to 78% in 2001. Some 41% of pupils from comprehensives took a language GCSE, compared to 81% of pupils in private schools.

Board said the government's attempts to boost languages were "limited by the wide choice of subjects available in schools, pressure on schools and pupils to achieve higher grades, and narrowly-focused advice from parents, tutors and others".

But a spokesman from the Department for Children, Schools and Families, said it was encouraging language learning by making languages compulsory for all seven- to 11-year-olds from 2011.

He said: "This is about creating a culture change in the way that we as a nation view languages – one which won't happen overnight. The key is getting pupils learning languages earlier, when they are more open and confident to start out. We need to break the link between parents who were put off learning foreign languages by starting too late, passing that on to the next generation."